Method for solvent bonding non-porous materials to automatically create variable bond characteristics

ABSTRACT

A method and apparatus for preengineering a solvent bond is disclosed. It creates the possibility of preestablishing designs to self-optimize the characteristics of the resultant solvent bond. These characteristics can thus be chosen by the part designer with confidence that inherent variations in the assembly process will not unduly impact the resultant bond. Setting the volume of dissolved material with acting upon it in the dissolved state are included.

BACKGROUND OF THE INVENTION

Generally the invention relates to the field of solvent bonding.Specifically, the invention relates to the action of the solvent itselfto create a bond between at least two parts. In terms of the knowledgeand skills involved, it is distinguished from such fields as the fieldof designing parts which may be bonded together to perform specificpurposes, the field of devices to introduce solvent to parts forbonding, and the field of particular chemicals to serve as a solvent.

For many years the technique of joining two parts together through theaction of a solvent has been utilized with varying degrees of success.The basic technique simply involves the introduction of a solvent to twosurfaces which are then dissolved and which bond together after thesolvent evaporates away. Perhaps due to the simplistic basis for thetechnique of solvent bonding, efforts at refining the technique havegenerally been based upon an assumption that the resultant bond shouldobviously be as strong as possible. Importantly, the present inventiondeparts from this assumption and provides a technique through whichbonds having a variety of characteristics can be repeatedly created.From the designer's perspective, the invention allows the particularcharacteristic (or combinations thereof) to be predetermined asappropriate for the particular application. The chosen characteristicsare then created automatically through the action of the solvent itself.In so doing, this technique allows the designer the freedom to choose anend result which may have characteristics within a broad range ofpossibilities. These characteristics include--but of course, are notlimited to--the resultant bond's: strength, ability to seal, appearance,failure mode, etc. Significantly, the present invention affords thedesigner the opportunity to confidently know that the characteristicswill be automatically created through the action of the solvent itselfrather than through some manipulation or supervision at the assemblylevel.

Prior to the present invention, those skilled in the art of solventbonding, seemed to focus their efforts in directions which might becharacterized as either: i) efforts designed to control incidentaleffects of the bonding process, or ii) efforts to externally control theprocess to create the bond. This is perhaps due to the preconceptions ofthose involved that, of course, the strongest bond possible was alwaysdesired. Representative of the types of improvements directed towardcontrolling the incidental effects of the bonding process are severalpatents. In. U.S. Pat. No 4,651,382 to Krolick, a blocking moat designwas disclosed to act as a barrier to prevent solvent from penetratingundesirable areas. In applications such as a door hinge, the moat servedto avoid the introduction of the solvent to the moveable parts of thehinge itself and thus avoid an undesirable incidental effect of thesolvent bonding process. Similarly, U.S. Pat. Nos. 4,256,333, 4,181,549,and 4,137,117 each disclosed designs for a solvent bonded joint whichavoided the incidental effect of contamination by the solvent ofmedically pure fluids. In all of these cases, the inventors designedelements which would act to control some consequential effect of thebonding process. Notably, none of these inventions concern themselveswith the characteristics of the resultant bond or--more to thepoint--with the automatic creation of specific bond characteristics.

The second group of directions those skilled in the art have taken hasbeen the direction of externally controlling the bonding process.Interestingly in many of these types of improvements, thecharacteristics of the bond itself are not even mentioned.Representative of this direction is U.S. Pat. No. 4,595,446 to Newkirkfor an apparatus which automates the application of solvent. ThroughNewkirk's invention, improvement to devices which create the bond aredisclosed. Again, no consideration is given to the characteristics ofthe resultant bond itself. Rather, through lack of comment, there is atacit acknowledgement that when it comes to the resultant bond, thesolvent itself creates a bond having some characteristics and thosecharacteristics are out of the designer's control.

The presupposition prior to the present invention that thecharacteristics of the bond itself were not controllable by the designerwas most likely due to a bias by those skilled in the art to create thestrongest bond in all instances. This is perhaps understood once it isrealized that the creation of the solvent bond was generallyaccomplished as an assembly function. Thus, assemblers created the bond.These persons usually not only possessed a lesser degree of skill thandesigners but they usually also had little latitude in impactingimprovements to the designs. These effects therefore lead to a focus ontrial and error efforts or on solvent metering devices rather thanunique part designs. This trial and error based level of expertiseresulted in a field which may be characterized by slow, incrementalimprovement rather than dramatic innovation on a wide scale. Thetechnology simply was not viewed as a highly sophisticated technology,rather it was viewed as a rather simple art in which minor improvementsare the norm. Surprisingly, the need for and usefulness of bonds havingvariable characteristics which are automatically created through theaction of the solvent has existed for some time. It is also true thatthe implementing arts and elements have been readily availablethroughout this time as well. Those skilled in the art simply did notappreciate the aspect of allowing for variable characteristics in thebond because they tended to assume that the strongest bond possible wasalways desired. This teaching away from the technical direction of thepresent invention was perhaps bolstered by unrelated arts such as heatbonding materials in which it is also assumed that the strongest bondpossible is the most desirable.

SUMMARY OF THE INVENTION

Accordingly it is an object of the present invention to alert thoseskilled in the art of solvent bonding to the possibility of engineeringthe resultant characteristics of the bond itself rather than eitherassuming that the strongest bond is always desirable or merely acceptingwhatever type of bond that naturally occurs. Keeping with this broadlystated object, it is a goal of the invention to allow the designer atechnique to simply assure that the chosen characteristics will becreated upon production of the solvent bond. It is also an object toprovide an invention which affords the designer the confidence of havingsuch characteristics automatically created through the interaction ofhis or her design and the solvent rather than through reliance on someskill at the assembly level.

A further object of the present invention is to provide a techniquethrough which changes to the characteristics of a resultant bond can beeffected. An important attribute of this technique is that it not onlyallows for a variety of characteristics, but that it assures that thechosen characteristics be created. In keeping with this desire it is anobject of the present invention to minimize or even avoid theconsequences of inherent variations in both assembly technique andcomponent manufacture on the characteristics of the resultant bond. Itis an aim of the present invention to make the chosen bondcharacteristics largely independent of such variations. In so doing, thepresent invention necessitates neither elimination nor inclusion ofmanufacturing variations; it simply makes them irrelevant.

Another broadly stated object of the present invention is to minimizethe need for assembler skill for creation of a proper solvent bond.Particularly it is a goal of the present invention to allow for creationof the chosen characteristics without relying on the particulartechniques or steps used to create the bond. In this regard it is anobject to make the resultant bond characteristics independent of thetechnique of introducing solvent to the assembly. It is also a goal tominimize or remove the impact of manufacturing variation on thecharacteristics of the bond created.

With respect to part design, it is a further object of the presentinvention to provide a way for the design of the parts themselves to setthe characteristics of the bond to be created. In so doing, it is thepurpose of the invention to allow the inherent properties of solvents toact so that they automatically create the desired characteristics.

Another broadly stated object of the present invention is to provide adesign having basic design parameters from which the designs may bederived to suit the specific criteria involved. Particularly it is agoal to provide an exemplary structure through which a broad range ofdesign parameters may be met by obvious variations.

Naturally, further objects of the invention are disclosed throughoutother areas of the specification and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of two parts to be bonded togetheraccording to the present invention.

FIG. 2 is an end view of the part to be bonded which has tabs on itssurface.

FIG. 3 is a side view in cross section of the two parts as assembledprior to the introduction of solvent.

FIG. 4 is a side view of that configuration depicted in FIG. 3 focusingon only the area to be bonded.

FIG. 5 is a side view in cross section of the two parts after theintroduction of solvent and after acting upon the viscous material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Although the drawings show a unique structure according to the presentinvention, the invention is more fundamentally understood through themethods involved rather than the one particular design disclosed. In afundamental sense, the preferred embodiment the present inventioninvolves the basic step of introducing solvent to create a bond with theunique steps of creating a set or predetermined volume of dissolvedmaterial and then acting upon the material while it is dissolved. Thesetwo steps each pose unique additions to the prior art techniques. Thesebasic steps significantly depart from the prior efforts by those skilledin the art not only in the steps themselves but in the fact that theyexpand the realm of design input to include the possibility ofengineering specific characteristics of the solvent bond. Significantlythese general concepts allow engineering of the solvent bond to occur atthe part design stage rather than during the assembly stage.

The aspect of creating a set volume of dissolved or viscous materialthrough a design of the parts has never been accomplished in the fashionof the present invention. According to the invention the designer candetermine the appropriate volume of viscous material prior to itscreation. This differs significantly from the prior art in which theamount of viscous material was simply happenstance in systems which didnot include the need to meter solvent during the assembly phase. In therelevant prior art the amount of viscous material created was dependentupon uncontrolled factors such as the imperfections of the surfaces tobe bonded and the technique of the particular assembler. A keydifference for the present invention is that the volume of viscousmaterial is predetermined at an amount which is optimally desirable forthe particular characteristics desired in the final solvent bond.

The predetermination of the volume of viscous material can beaccomplished in a variety of ways. Again, although the structure of thepresent invention is unique, the general techniques disclosed encompassa much broader scope as they open up a great possibility of designs.Certainly, the more traditional technique of externally metering thesolvent introduced to the parts could be utilized. Although this, whencombined with the second step of acting upon the parts while they aredissolved, falls within the scope of the present invention, it does notprovide the self-optimization aspects of the other techniques disclosed.

To achieve the goal of self-optimization, the technique of creating areservoir--that is a space between the two parts--which defines aspecific volume has been developed. By defining a set volume thereservoir acts to automatically create the appropriate volume of viscousmaterial for the desired characteristics. Certainly a variety oftechniques could be used to create the reservoir. Again, one couldsimply separate the parts manually during assembly. This would, ofcourse, defeat several objects of the present invention, namely, that ofself-optimization and that of minimizing assembler actions. Thereservoir could also be created through use of internal or externalspacers which automatically create the desired reservoir volume. Byhaving a set thickness, the spacers would act to create a set volume.This type of technique not only meets the basic requirements of thepresent invention but it also accomplishes the goals ofself-optimization and minimizing any need for manual techniques at theassembly phase. It also enhances the consistency and reproductibility ofspecific characteristics by removing variables. If an external spacer isemployed, it simply would be removed--without moving the parts relativeto each other--prior to filling the reservoir with solvent.

Once the reservoir has been created, solvent is introduced to completelyfill the reservoir. The solvent then acts upon the surfaces to create avolume of dissolved or viscous material. At some point the spacer mustbe removed to allow for the second step of acting upon the viscousmaterial. The removal of the spacer can be accomplished in a variety ofways, including either manual or chemical removal. In a manual instancethe spacer would be physically removed from between the parts. Again,although this falls within the scope of the present invention it doesnot allow achieval of the goal of self-optimization. A more preferableway to remove the spacer is to allow it to be chemically dissolved. Thisis a particularly desirable technique when the spacer is designed to bea series of tabs or protrusions on one or more of the surfaces. Whentabs are used, it would be desirable to provide for their dissolving tobe substantially complete at exactly the time when the desired amount ofdissolving of the surfaces has occurred. This can be accomplishedthrough proper sizing of the tabs such that each tab's width is lessthan or equal to twice its height. In this fashion the tab will besubstantially dissolved--that is dissolved enough to allow the desiredamount of action upon the viscous material--at the proper time thusallowing the surfaces themselves to act to time any action (as discussedbelow) upon the viscous material. This dissolving would, of course,occur prior to the actual curing of the viscous material.

The second general aspect of the present invention is the concept ofacting upon the viscous material prior to its being cured. This differsdrastically from the prior art. In the prior art, action upon theviscous material was generally avoided rather than specificallyincluded. By acting upon the viscous material, it is meant that any typeof action could be included, the object being simply the accomplishmentof one or more of the following goals. First, a goal would be to mix theviscous material. This would assure that the viscous material has auniform consistency and thus upon curing, that the bond itself wouldhave uniform characteristics throughout. The second goal of acting uponthe viscous material would be that of eliminating any pockets of solventor any areas where the solvent has not been able to dissolve thesurface. Since imperfections at even a microscopic level will alwaysremain, this step accommodates the practical aspects of creating solventbonds. A third goal would be that of substantially purging impuritiesfrom the viscous material. Since such parts are rarely manufactured orhandled in a clean-room environment, impurities to the surfaces to bedissolved are often introduced. These impurities are a detriment to thecreation of the theoretically optimal solvent bond and so should beeliminated to the degree possible. By acting upon the parts while theviscous material exists, these impurities can be substantially purged.It should be understood that total elimination is rarely accomplished.Rather, by the use of the term "substantially purged" it is meant thatsuch impurities be reduced to the largest degree practical.

As mentioned the action upon the viscous material can be accomplished ina variety of ways. These could range from sophisticated techniques suchas the use of ultrasound or external conditions to the step of simplydisplacing one part with respect to the other. Although the former rangeof possibilities might seem more highly technical and therefore moreable to be controlled, they do not achieve the goal of minimizing anyinput at the assembly level. Rather the step of simply displacing onepart with respect to the other accomplishes this very easily withminimal impact upon the assembly phase. This displacement would includea variety of techniques such as simply "squishing" the parts together toonly twisting one part with respect to the other. As explained later, byapplying a set force manually to compact the parts and thus "squish" theviscous material, several ends are achieved. First, displacement betweenthe two parts occurs. This serves to mix the viscous material to someextent. Second, when the volume of viscous material is reduced, movementof the material perpendicular to the direction of displacement of theparts will occur. This not only enhances mixing the viscous material butit also aids in eliminating any pockets of solvent or non-solvent.Finally, by reducing the volume some of the viscous material is removed.Since the surface itself would contain the greatest degree of impuritiesand since that surface would be the first to be dissolved, thus it wouldalso be the most fluid material. It would thus tend to be removed first.This would thus aid in elimination of any impurities existing.

In considering the amount of displacement desirable, at least an amountof displacement equal to the largest surface deviation should beincluded. In this way the bond may be optimized according to thespecific parts provided. As mentioned, the displacement can includedecreasing the volume of viscous material (i.e. "squishing" it).Interestingly, the process through which a solvent bond is created issuch that the decrease in viscous material cannot practically beoverdone. Once impurities are substantially reduced, only a minimalamount of solvent is actually necessary to achieve a bond as would bemost desirable in a great variety of conditions. This step of decreasingthe volume of viscous material not only achieves the three goalsmentioned above but it also has the effect of accomplishing otherdesirable characteristics such as reducing any gaps in the bondedportion, reducing any interstitials that may b contained within theparts themselves, etc.

In addition to the two basic steps of creating a set volume of viscousmaterial and acting upon that material while it is dissolved, themethods may include the additional step of acting upon the viscousmaterial at the optimal time. This time may be determined not simplyupon the passage of time but, more accurately, upon the amount ofviscous material created or the degree of dissolving having occurred.While certainly this could be empirically tied to the passage of time,the fact that solvent bonds are created in a variety of conditions,temperatures, pressures, and the like, makes the simple elapse of timeless effective in optimizing the action upon the viscous material. Bybasing the action upon the amount of dissolving having occurred, theselimitations can be avoided. Significantly the present invention affordsthe opportunity of automatically determining the optimum amount ofdissolving having occurred. This again achieves the desired goal ofminimizing the need for input or decisions at the assembly phase andenhances the avoidance of any variations in the resulting bond. It isaccomplished by designing the tabs or spacers to substantially dissolveat the appropriate point. Thus by applying a small force to the parts,the force causes a displacement only when the appropriate amount ofdissolving of the surfaces has occurred. Again, the extraordinarysimplicity of this technique allows it to achieve the desired goals withminimal impact at the assembly phase.

As mentioned earlier, solvent may be introduced to the joint in thetraditional fashion. This could involve introducing solvent to at leastone of the surfaces and then joining the surfaces together. To simplifythe impact of the assembly process, an enhanced technique of introducingthe solvent to the area to be bonded is provided. This involvesdesigning the surfaces such that the solvent is distributed through itsown natural properties--most notably the property of capillary action.In so doing not only can the solvent be certainly distributed throughoutthe entire area involved (through the designer's input of course) buteven the pattern of distribution can be affected through proper designs.At the assembly phase, this feature can considerably simplify theintroduction of solvent. Through proper design the possibility of evendipping the part in solvent exists without over introducing solvent tothe area to be bonded. By allowing for the distribution of solvent tooccur through the solvents natural properties, the present inventionallows the solvent itself to be a controlling factor in assuring theproper characteristics. Thus the characteristics are created independentof the technique used by the assembler of introducing the solvent to theparts. Again, this enhancement serves to achieve the desired goal ofself-optimizing the process so that the designer can have a greaterdegree of certainty that the desired characteristics will in fact becreated. The distribution of the solvent thus serves as a way ofassuring the creation of the desired characteristic or characteristics.

To accomplish the appropriate distribution of the solvent throughcapillary action, the designer can design the part such that solventwill only be distributed in certain areas or will be distributedthroughout the entire surfaces. In this fashion a solvent bond on anon-porous surface can be greatly impacted by the design of the parts.In so doing the operation of the surfaces act to create thecharacteristics independent of the variation inherent to any assemblyprocess.

An ancillary benefit to the creation of a reservoir and the use ofcapillary action is the possibility of increasing the volume of viscousmaterial beyond that typically possible in traditional manualtechniques. In some instances the specific solvents involved evaporateso quickly that repeated application of the solvent is required in orderto achieve the proper amount of dissolving. As an example, the use ofmethyl chloride--which boils in ones hand--requires repeatedapplications in most situations. The present invention accommodates thischaracteristic by isolating the solvent within a reservoir as previouslydiscussed. Through the use of capillary action and the use of a setreservoir, greater volumes of solvent, and therefore greater volumes ofviscous material, can be created without the need for repeatedapplication of the solvent.

In utilizing capillary action, it should be noted that in many designinstances it may be desirable to provide for parallel surfaces. Incontrast to the prior art in which tapered surfaces were utilized,capillary action will work on parallel surfaces as well. In addition,through using parallel surfaces a more even bond can be created suchthat equal amounts of solvent per unit surface area will be introduced.In contrast, the prior art which utilized divergent surfaces would causethe majority of bonding to occur at the surfaces' most narrow point.

From the perspective of the scope of the present invention, it should beunderstood that the methods disclosed herein are shown in their mostfundamental forms for the purposes of expanding the great variety ofdesign possibilities. Since each method could be varied and combined indifferent ways to achieve specific characteristics for a particularapplication, such variations are intended not only to fall within thescope of the present invention but also to be pursued as each situationmay warrant. In keeping with this goal only the most basic designconcepts and structure are discussed. Specific applications andmodifications can be readily achieved by those skilled in the art oncethe basic concepts are understood.

As mentioned a basic structure is also disclosed. Referring to FIG. 1,it can be seen that the invention is shown on a representative item, inthis case a barbed fitting. The fitting is composed of a male part (1)and a female part (2) which are to be solvent bonded together. Both malepart (1) and female part (2) include a cylindrically shaped shoulder (3)which terminates in the bonding surface (4). As can be seen on male part(1), bonding surface (4) has integral to it a series of tabs (5). Thesetabs (5) extend for a great portion of the width of bonding surface (4).In the vicinity of bonding surface (4) on male part (1), is male sleeve(6). Male sleeve (6) is designed to fit into female sleeve (7) and thusserves to hold the parts in a fixed relationship, to one another inthree-dimensional space prior to creation of the solvent bond. Suchsleeves should not hold the parts too securely after the bond is createdso that any inherent movement necessary during curing is possible.

Referring to FIG. 2 it can be seen that several tabs (5) are included onbonding surface (4) of male part (1). Naturally the tabs could becombined on either male part (I) or female part (2) or could beseparately included as discussed earlier. Importantly in this particularembodiment, there are at least three tabs (5). This serves to provide aplaner support for the two parts relative to each other such thatbonding surfaces (4) can be held in parallel relationship. Naturally avariety of shapes for tabs (5) could be provided. In addition, tabs (5)could actually be a series of bumps or protrusions on one or more of thebonding surfaces (4).

In creating the solvent bond, male part (1) and female part (2) may befitted together such that male sleeve (6) fits within female sleeve (7)and such that tabs (5) of male part (1) touch bonding surface (4) offemale part (2). This creates a set reservoir (8) between male part (1)and female part (2). This reservoir has then introduced to it thesolvent to create the solvent bond.

As can be seen through FIGS. 3 and 4, reservoir (8) is defined bybonding surfaces (4) being held a fixed distance apart. This fixeddistance (X) is substantially constant across most areas of bondingsurfaces (4). Thus, bonding surfaces (4) are parallel to one another.

Once solvent is introduced, capillary action will cause the solvent towick throughout all areas of bonding surfaces (4). In order tofacilitate wicking about the four areas of bonding surfaces (4) definedby the four tabs (5), fluid connection between each area is provided.Referring to FIG. 4 it can be seen that this fluid connection isprovided through rounding the inner edge (9) of bonding surface (4) offemale part (2). In order to facilitate fluid connection, it isdesirable that the opening created by rounding of the inner edge (9) ofthis female bonding surface be sufficiently large such that the meniscuscreated by the solvent be able to pull solvent through the opening. Thisthus serves as a means for distributing the solvent that is integral tothe part design.

Referring also to FIG. 4 it can be seen that tab (5) when viewed on endhas a width (W) and a height (H). Certainly height (H) will be equal tofixed distance (X) which separates bonding surfaces (4). Importantly,width (W) is no more than twice height (H). This allows the dissolvingof tab (5) to occur at the proper time. Naturally width (W) could besubstantially less than height (H) in instances where a lesser amount ofviscous material is desired. In this fashion tab (5) will substantiallydissolve prior to the full amount of dissolving possible. Tab (5) couldalso have a stepped shape.

Referring to FIGS. 4 and 5, it can be seen that once solvent isintroduced to reservoir (8), a volume of viscous material is created.The decrease in this volume is effected by simply displacing male part(1) and female part (2) together as shown by the arrows. This effects adecrease in fixed distance (X) and will decrease the amount of viscousmaterial by forcing some outside the solvent bonded area in the externalvicinity of shoulders (3). This affords the advantages discussedearlier. After the displacement, the parts are left to cure such that asolvent bond is created in the area where bonding surfaces (4) existed.Since one integral part is now created, bonding surfaces (4) now ceaseto exist and are replaced by solvent bonded area (10).

Curing can then be accomplished by simply letting the parts dry--that isallowing the solvent to evaporate from all locations within solventbonded area (10). To achieve an optimum bond, male part (1) and femalepart (2) should be free to move with respect to each other and shrink asmay naturally occur. Importantly, male sleeve (6) and female sleeve (7)should remain free to move with respect to one another. In addition somesmall clearance (11) may optimally be included to assure that male part(I) and female part (2) are not held apart undesirably.

Again, this structure represents a relatively simple representativestructure to accomplish the methods of the present invention. Theforegoing discussion and the claims which follow describe the preferredembodiments only. Particularly with respect to the claims it should beunderstood that changes may be made without departing from theiressence. In this regard it is intended that such changes would stillfall within the scope of the present invention. It simply is notpractical to describe and claim all possible revisions to the presentinvention which may be accomplished. To the extent such revisionsutilize the essence of the present invention, each would naturally fallwithin the breath of protection encompassed by this patent. This isparticularly true for the present invention since its basic concepts andunderstandings are fundamental in nature and are intended to open anopportunity for engineers to specifically preengineer solvent bondedjoints to accomplish the particular characteristics desirable for theirapplication.

I claim:
 1. A method of creating an engineered solvent bond between twoitems each having a nonporous surface to be bonded to the othercomprising the steps of:a. predetermining the volume of viscous materialto be created; then b. providing at least one spacer between saidsurfaces; c. removing said at least one spacer; d. applying a solventbetween the surfaces to be bonded; then e. creating an appropriatevolume of viscous material through action of said solvent in dissolvingthe surfaces; then f. acting upon the surfaces while they are in adissolved state in order to intermix said viscous material from bothsurfaces; then g. curing said surfaces to eliminate said viscousmaterial and create a bonded joint.
 2. A method of creating anengineered solvent bond between two nonporous surfaces as described inclaim 1 and further comprising the step of substantially dissolving saidat least one spacer while accomplishing the step of creating the volumeof viscous material.
 3. A method of creating an engineered solvent bondbetween two nonporous surfaces as described in claim 2 and furthercomprising the step of applying a predetermined force for the purpose ofeventually effecting a displacement of the surfaces, said step ofapplying occurring prior to accomplishing the step of applying thesolvent between the surfaces to be bonded.
 4. A method of creating anengineered solvent bond between two nonporous surfaces as described inclaim 2 and further comprising the step of applying a predeterminedforce for the purpose of eventually effecting a displacement of thesurfaces, said step of applying occurring prior to accomplishing thestep of substantially dissolving said at least one spacer.
 5. A methodof creating an engineered solvent bond between two items each having anonporous surface to be bonded to the other comprising the steps of:a.predeterming the volume of viscous material to be created; then b.applying a solvent between the surfaces to be bonded; then c. creatingan appropriate volume of viscous material through action of said solventin dissolving the surfaces; then d. acting upon the surfaces while theyare in a dissolved state in order to intermix said viscous material fromboth surfaces, wherein said step of acting comprises the steps of:i.displacing one of said surfaces with respect to the other surface; andii. timing said displacement to occur at a consistent point during thedissolving of said surfaces based upon the amount of dissolving havingoccurred; then e. curing said surfaces to eliminate said viscousmaterial and create a bonded joint.
 6. A method of creating anengineered solvent bond between two nonporous surfaces as described inclaim 5 wherein said point during the dissolving is automaticallydetermined.
 7. A method of creating an engineered solvent bond betweentwo nonporous surfaces as described in claim 6 wherein said step oftiming said displacement is determined through operation of saidsurfaces.
 8. A method of creating an engineered solvent bond between twononporous surfaces as described in claim 7 wherein said surfacecomprises an integral spacer and wherein said step of acting to timesaid displacement comprises the step of substantially dissolving thespacer.
 9. A method of creating an engineered solvent bond between twononporous surfaces as described in claim 8 and further comprising thestep of freeing said items to move relative to each other whileaccomplishing the step of curing said surfaces.
 10. A method of creatingan engineered solvent bond to join at least two nonporous surfacestogether at a planar surface comprising the steps of:a. determining thedesired characteristics of the bond to be created; b. predetermining thevolume of viscous material necessary to produce said desiredcharacteristics; then c. establishing an appropriate capillarydistribution for a solvent, then; d. applying said solvent to create thebond to at least one of the surface to be bonded; then e. assuring thecreation of the desired characteristics of bond through action of saidsolvent, wherein said action of said solvent dissolves at least one ofsaid surfaces to produce a volume of viscous material, and wherein saidstep of assuring the desired characteristics comprises the step ofdistributing the solvent in a predetermined manner throughout saidplanar surface wherein said solvent has the property of capillary actionand wherein said step of distributing the solvent is achievedautomatically through the capillary action of said solvent; and then f.acting upon said surface while dissolved in order to intermix saidviscous material properly; then g. curing said bond to create anassembly having the desired characteristics.
 11. A method of creating anengineered solvent bond to join at least two nonporous surfaces togetheras described in claim 10 wherein said step of establishing theappropriate capillary distribution comprises the step of creating areservoir having a predetermined volume between said surfaces into whichthe solvent will be applied.
 12. A method of creating an engineeredsolvent bond to join at least two nonporous surfaces together asdescribed in claim 11 wherein said step of creating the reservoircomprises the step of utilizing a spacer having a predeterminedthickness between the surfaces to be bonded.
 13. A method of creating anengineered solvent bond to join at least two nonporous surfaces togetheras described in claim 12 wherein said step of utilizing a spacercomprises the step of making said spacer integral to at least one ofsaid surfaces.
 14. A method of creating an engineered solvent bond tojoin at least two nonporous surfaces together as described in claim 13wherein said step of making said spacer integral comprises the step ofproviding protrusions on said surface.
 15. A method of creating anengineering solvent bond to join at least two nonporous surfacestogether as described in claim 14 and further comprising the step ofsubstantially dissolving said spacer prior to said step of curing thebond.
 16. A method of creating an engineered solvent bond to join atleast two nonporous surfaces together as described in claim 12 andfurther comprising the step of removing said spacer without changing therelative positions of said surfaces to be bonded prior to said step ofapplying the solvent.
 17. A method of creating an engineered solventbond having desired characteristics between two items each having anonporous surface to be bonded to the other comprising the steps of:a.predetermining an appropriate volume of viscous material necessary toproduce said desired bond characteristics; then b. determining thevolume of solvent desirable to create the appropriate volume of viscousmaterial; and then c. placing said surfaces in proximity to each other;and then d. establishing a reservoir having a predetermined volumebetween said surfaces and into which the solvent will be applied,wherein the predetermined volume of the reservoir is substantially equalto the volume of solvent desired; and then e. completely filling saidreservoir with said solvent; thus f. applying said solvent between saidsurfaces to be bonded; and then g. dissolving said surfaces to createsaid volume of viscous material to create a solvent bond; and then h.acting upon said surfaces while dissolved in order to intermix saidviscous material.
 18. A method of creating an engineered solvent bondhaving desired characteristics between two items each having a nonporoussurface to be bonded to the other as described in claim 17 and furthercomprising the step of decreasing the volume of said reservoir toeliminate some of said viscous material at some point duringaccomplishing the step of dissolving said surfaces.
 19. A method ofcreating an engineered solvent bond having desired characteristicsbetween two items each having a nonporous surface to be bonded to theother as described in claim 18 and further comprising the step of timingsaid step of decreasing the volume of said viscous material based uponthe amount of dissolving having occurred.
 20. A method of creating anengineered solvent bond having desired characteristics between two itemseach having a nonporous surface to be bonded to the other as describedin claim 19 and further comprising the step of applying a force todecrease the volume of said reservoir while accomplishing said step ofdissolving said surfaces.
 21. A method of creating an engineered solventbond having desired characteristics between two items each having anonporous surface to be bonded to the other as described in claim 19 andfurther comprising the step of applying a force to decrease the volumeof said reservoir prior to accomplishing the step of applying thesolvent between the surfaces to be bonded.
 22. A method of creating anengineered solvent bond having desired characteristics between two itemseach having a nonporous surface to be bonded to the other as describedin claim 20 and further comprising the step of automatically determiningthe amount of dissolving appropriate to initiate the step of decreasingthe volume of said reservoir.
 23. A method of creating and engineeredsolvent bond having desired characteristics between two items eachhaving a nonporous surface to be bonded to the other as described inclaim 22 wherein said reservoir is established by at least one spacer,and said step of automatically determining the amount of dissolving isdetermined by substantially dissolving said at least one spacer.